copy_xstate_to_uabi_buf(9)

💖 NAME 💖

copy_xstate_to_uabi_buf — Copy kernel saved xstate to a UABI buffer. This is the copy_xstate_to_uabi_buf(9) page from the Kernel API Manual, bestie, and we're keeping it cute and complete. ✨

🌈 SYNOPSIS 🌈

void copy_xstate_to_uabi_buf (struct membuf to , struct task_struct *tsk
, enum xstate_copy_mode copy_mode );

🎀 ARGUMENTS 🎀

• to — membuf descriptor. Literally the descriptor, okay?
• tsk — The task from which to copy the saved xstate.
• copy_mode — The requested copy mode.

🦋 DESCRIPTION 🦋

Okay so this one converts from kernel XSAVE or XSAVES compacted format to UABI conforming format, i.e. from the kernel internal hardware dependent storage format to the requested mode. And the vibe check: UABI XSTATE is always uncompacted! No cap. 💅

It supports partial copy, but to.pos always starts from zero. That's the rule, bestie.

👑 SEE ALSO 👑

• Kernel file ./arch/x86/kernel/fpu/xstate.c
• check_xtile_data_against_struct(9)
• __copy_xstate_to_uabi_buf(9)
• copy_uabi_to_xstate(9)
• xsaves(9)
• xrstors(9)
• fpstate_realloc(9)
• fpu_xstate_prctl(9)

Sign-off cuteness: this page comes from ./arch/x86/kernel/fpu, dated October 2026, and it's all for copy_xstate_to_uabi_buf(9). Stay iconic, bestie. 🫶💖